there are far more onerous aspects to check when towing than worrying solely about weight ratios. Put your big boy pants on and mention: Nose weight, tyre pressures, weight distribution in the caravan, tyre condition, condition of car and car suspension, does the van have ATC? Has the driver been on a towing course? To name but a few. This is precisely why the focus on the 85% ratio is absurd and distracts from all those other elements which contribute to safe towing.